Celebration of Discipline 

by Richard Foster

This is a spiritual classic. This book teaches you step by step how to fast, how to pray, how to do many different disciplines of spiritual development. It is a must have for those who want to know how to live a spiritual life. The only drawback is that it is a little thin on the depth of understanding that is present in the Eucharist. But we need to remember that it was written by a Quaker and Quakers do not believe in sacraments. Other than that precaution, there is much to be learned from Foster.